Mobile Module 2
While the MMC-1 Module used a PCI Interface to connect to the Notebook Motherboard the MMC-2 (Mobile Module Connector 2) used an AGP/PCI Interface.
MMC-2 Connector View
The MMC-2 has 10 rows and 400 pins. It is not possible to use an MMC-1 Module in an MMC-2 slot or vice versa. The BX chipset used with the mobile modules always supports AGP, but the connector of the MMC-1 doesn't allow it's use. The MMC-2 processors kicked-off AGP graphics inside of a notebook for 3D graphics and better DVD playback.
Like the Pentium II MMC-1 Module the Pentium II MMC-2 module uses 1.6V.
Also the advantage of the on-die cache is obvious. On-die level two cache not only reduces the weight of the module by ~4g, but also saves valuable power.
The MMC-2 Celeron is a bridge to the next step in the evolution of mobile CPUs.